Thank you m and Anik, and sorry for hijacking

My vase is 18 cm tall.
And you are right, blue pieces (even the more common shapes) seem to be more sought after than others.
Mine is from a local fleamarket, and cost 5,- Euro, so I can live happily with the damage; the annoying thing is that the seller asked 15,- Euro before I hinted at the chip -- that would have been a great bargain...
Michael